Imprisoned killer beaten to death in Shirley

SHIRLEY — Authorities are investigating the killing of a 72-year-old inmate Tuesday at Souza-Baranowski Correctional Center on the Lancaster-Shirley line.

According to the Worcester district attorney's office, William Sires, convicted of the 1973 murder of his mother in Pittsfield, was found badly beaten and near death in a cell on Tier N1 about 2 p.m. Tuesday.

The district attorney's office said he was pronounced dead in an ambulance about 2:36 p.m. on the way to HealthAlliance Hospital — Leominster.

State police detectives assigned to the Worcester district attorney's office and the Department of Correction are investigating.